It is estimated that there will be more than 130,000 new cases of colorectal cancer diagnosed in the United States this year, placing cancer at this anatomic site among the three leading high incidence cancers. Colorectal cancer almost always develops from a precursor lesion, the adenoma. Current practice in the community regarding follow-up surveillance of patients after polypectomy is variable. A randomized controlled trial was designed to evaluate strategies for the surveillance of post-polypectomy patients for the control of large bowel cancer. Patients are eligible for the study if they have an adenoma removed during total colonoscopy, have no inflammatory bowel disease or colon cancer, have no previous polypectomy, no history of familial polyposis, no invasive cancer in the polyp, and no sessile adenomas larger than 3 cm. Eligible patients are stratified and then randomized into either a 1 and 3 year follow-up arm or a 3 year follow-up arm. The following questions will be addressed: (1) Of the strategies offered within the study, which is the follow-up method that will detect clinically significant neoplasia more effectively? Factors to be considered will be timing, type of exam and interval testing. (2) Can data obtained at enrollment serve as predictive factors of recurrence? (3) What is the association of family history of colorectal and other cancer with size, number, distribution, pathology, and recurrence of adenomas? (4) What is the impact of the strategies offered on the future incidence of colorectal cancer? Additional secondary aims are: Can the natural history of the colorectal adenoma and its relationship to colorectal cancer be clarified by examination of baseline and recurrence data? Is there a need for surgical resection in patients found on initial examination to have a pedunculated adenoma with invasive cancer? What are the risk/benefit considerations? In order to answer the above questions, the program design for the renewal period includes: continuation of enrollment and randomization; continuation of follow-up of currently enrolled patients with an annual questionnaire and fecal occult blood test, and at 6 years with a complete colonoscopy and double contrast barium enema; and implementation of a validated family history questionnaire. The data from this program will allow recommendations to be made for general guidelines for surveillance of this high risk group. In addition, the impact of these strategies on future incidence of colorectal cancer will have critical importance.